Plants known in the state of the art for the production of long rolled products provide a casting machine and a rolling mill, which is disposed in line and downstream of the casting machine. It is also known that, in the solutions in which the casting axis defined by the casting machine and the rolling axis defined by the rolling mill coincide, the plant can be configured and used in endless (or continuous) mode, or in semi-endless mode (that is, starting from segments of cast products sheared to size).
In these operating solutions, if the rolling mill stops, either accidentally, for example due to cobbles, or programmed, for example to change channels or change production, it is necessary to stop the rolling process, which also entails the interruption of the casting machine; moreover, if the rolling mill stops accidentally it makes it necessary to scrap at least part of the intermediate material between the casting and the stopping point, and also the material being processed from the tundish to the rolling mill.
Consequently, any stoppage of the rolling mill causes a reduction in productivity and the plant utilization factor, an increase in the management costs and they are the main cause of an increase in energy required.
One purpose of the present invention is therefore to achieve an in-line casting and continuous rolling process, endless or semi-endless, and to perfect a relative production plant which allows to manage the stopping of the rolling mill, substantially without interrupting the casting and therefore without loss of production and without penalizing the steel plant upstream.
Another purpose of the invention is to reduce to a minimum or eliminate the scrap material in emergency situations or during programmed stoppages and so completely recover the product which in these situations is temporarily accumulated in an intermediate point along the production line.
Another purpose of the invention is to exploit to the utmost the enthalpy possessed by the original liquid steel along all the production line in order to obtain a considerable energy saving and a reduction in running costs compared with conventional processes.
Further purposes of the present invention are:                to guarantee a higher yield, equal to the ratio between weight of the finished product and weight of the liquid steel to produce a ton,        to obtain a greater stability of the rolling mill and a better dimensional quality of the finished product;        to guarantee the possibility of changes in production in dimension and type without stopping the continuous casting, obtaining a higher plant utilization factor.        
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.